Rashi there, is of the opinion that although the Mishna discusses the burning of the fats in the above text, it only mentions this mitzvah (commandment) in passing—in regards to those things whose time limit is until dawn. The Sages’ decree though, of “until midnight,” stated at the end of the Mishna, is only regarding the recitation of the Shema, and not in regard to the burning of the fats and limbs. Rambam (Maimonides) though, is of the opinion that the Sages indeed enacted an edict that one should not burn these fats as well, past midnight. This can be seen in the following statement of Rambam:
Text 4
The limbs of the burnt-offerings may be offered on the fire of the altar until dawn. In order to distance [a person] from inadvertent transgression, our Sages declared that the fats and the limbs of the burnt-offerings should only be offered on the fire of the altar until midnight. Rambam, Masei HaKorbanos 4:2
Rambam is of the opinion that the injunction of the Sages to prevent transgression applies to the burning of the limbs and fats as well, while Rashi is of the opinion that this restriction was only said regarding the recitation of the Shema but not enacted concerning burning the fats and limbs.
Rashi’s reasoning
The reason why Rashi differs from the Rambam is because the Torah explicitly stated that the sacrifice “burns on the altar all night until morning.” Being that the Torah explicitly permitted that the sacrifice may burn on the altar the entire night, the Sages had no right to limit that time until midnight.
Text 5
The Sages do not have the ability to prohibit something that the Torah explicitly said was permitted. The Sages only have the ability to be stringent in a situation where there is no prohibition or permission explicit in the Torah. However, when there is explicit permission in the Torah, they may not. Turei Zahav, Yora Deah 117:1
Since Rashi observed that the Torah explicitly permits the burning of the fats until dawn, he understood that the Sages’ prohibition “until midnight,” could not have possibly been said concerning the burning of the fats. According to this rule though, the opinion of Rambam is not understood: Why is Rambam of the opinion that one may only burn the fats and the limbs until midnight to prevent transgression, if the Sages were, in fact, unable to prohibit that which the Torah explicitly permitted?
Two forms of consumption
This can be understood through prefacing the comparison that the Talmud makes between the eating of the korban (sacrifice) by man and the consumption of the sacrifice atop the altar. When the Torah discusses the prohibition regarding not leaving any of the sacrifice uneaten after a prescribed time, the Torah says:
Vayikra, 7:18.
